Arm + KASAN + syzbot

[Russell King - ARM Linux admin]

On Thu, Mar 11, 2021 at 02:55:54PM +0100, Linus Walleij wrote:
> On Thu, Mar 11, 2021 at 11:54 AM Dmitry Vyukov <dvyukov at google.com> wrote:
> > The instance has KASAN disabled because Go binaries don't run on KASAN kernel:
> > https://lore.kernel.org/linux-arm-kernel/CACT4Y+YdJoNTqnBSELcEbcbVsKBtJfYUc7_GSXbUQfAJN3JyRg@mail.gmail.com/
> 
> I am still puzzled by this, but I still have the open question about how much
> memory the Go runtime really use. I am suspecting quite a lot, and the
> ARM32 instance isn't on par with any contemporary server or desktop
> when it comes to memory, it has ~2GB for a userspace program, after
> that bad things will happen: the machine will start thrashing.

I believe grafana is a Go binary - I run this in a VM with only 1G
of memory and no swap along with apache. It's happy enough.

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
grafana   1122  0.0  5.9 920344 60484 ?        Ssl  Feb18  28:31 /usr/sbin/grafana-server --config=/etc/grafana/grafana.ini ...

So, I suspect it's basically KASAN upsetting Go somehow that then
causes the memory usage to spiral out of control.

-- 
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